
use std::error::Error;
use std::{fs, env};

pub struct Config {
    pub query: String,
    pub file_path: String,
    pub ignore_case: bool,
}
    
impl Config {
   pub fn build(args: &[String]) -> Result<Config, &'static str> {
        if args.len() < 3 {
            return Err("not enough arguments!");
        }
        let query = args[1].clone();
        let file_path = args[2].clone();
        let ignore_case = env::var("IGNORE_CASE").is_ok();

        Ok(Config {query, file_path, ignore_case})
    }
}

pub fn run(config: Config) -> Result<(), Box<dyn Error>> {
    let contents = fs::read_to_string(config.file_path)?;
    // println!("With text:\n{contents}");

    // for line in search(&config.query, &contents) {
    //     println!("{line}");
    // }

    let results = if config.ignore_case {
        search_case_insensitive(&config.query, &contents)
    }else{
        search(&config.query, &contents)
    };

    for line in results{
        println!("{line}")
    }

    Ok(())
}

pub fn search<'a>(query: &str, contents: &'a str) -> Vec<&'a str>{
    // vec![]

    let mut results = Vec::new();

    for line in contents.lines() {
        if line.contains(query) {
            results.push(line);
        }
    }

    results
}

pub fn search_case_insensitive<'a>(
    query: &str, 
    contents: &'a str,
) -> Vec<&'a str>{
    let query = query.to_lowercase();
    let mut results = Vec::new();
    
    for line in contents.lines() {
        if line.to_lowercase().contains(&query) {
            results.push(line);
        }
    }

    results
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn one_result() {
        let query = "duct";
        let contents = "\
Rust:
safe, fast, productive.
Pick three.
Duct tape.";
        assert_eq!(vec!["safe, fast, productive."], search(query, contents));
    }

    #[test]
    fn case_insensitive() {
        let query = "rUsT";
        let contents = "\
Rust:
safe, fast, productive.
Pick three
Trust me.";

        assert_eq!(
            vec!["Rust:", "Trust me."],
            search_case_insensitive(query, contents)
        );
    }
}